Vehicle treatment implements such as washing brushes, polishing brushes and dryer nozzles, for purposes of this disclosure, can be divided into two categories: those which are located adjacent the side or lateral surfaces of the vehicle and are generally called "vertical" implements, and those which are disposed overhead and are generally referred to as "horizontal" implements. In the case of a washing or polishing brush, the lateral or vertical brushes typically contact and wash the side surfaces of the vehicle whereas the horizontal brush typically contacts the hood, windshield, top, rear window and rear deck surfaces of the vehicle. Either or both of lateral and overhead brushes can be manipulated to contact the front and rear surfaces depending on the design of a particular system.
It is common for overhead or horizontal brushes to be disposed between the free ends of relatively long support arms which are in turn pivotally connected to vertical support structures located on opposite sides of vehicle treatment locations such as a conveyor lane. The conventional arrangement is to locate the pivot points of the support arms well above the maximum height of the vehicles to be treated, with the arms extending from the pivot points downward and in the same direction as relative vehicle travel. The implement support arms are typically counterweighted to control the pressure or weight which the implement exerts on the vehicle such that as the vehicle progresses through the wash lane the implement, e.g. the brush, is gradually forced upwardly as it engages the contours of the vehicle and is then permitted to descend, either in a free fall or controlled fall, down the rear surfaces as the vehicle passes under and beyond the brush.
There are a number of problems, deficiencies and disadvantages associated with a brush arrangement of this type including the fact that the brush may fall too rapidly against the rear deck surface or may tend to float relative to the vehicle unless a proximity detecting control system is used. In addition such an arrangement may rely on the rotation direction of the brush to maintain proper spacing and/or pressure between the brush and surfaces of the vehicle and this brush rotation direction may be such as to lift and/or damage windshield wipers and other vehicle appendages. Similar problems, deficiencies and disadvantages exist in vertical implements supported in a comparable manner but using
Vertical implements may be supported in a comparable manner, but using some means other than gravity to bias the implement into contact with the vertical surface, and these arrangements may suffer from similar problems, deficiencies and disadvantages.